Auxin

Q.

Where is auxin synthesized in plants?

Q.

Which of the following hormone inhibits the growth of lateral buds and promotes the growth of terminal buds?

1. Abscisic acid

2. Gibberellin

3. Auxin

4. Ethylene

Q.

Is Auxin destroyed by light?

Q.

Where the auxins are synthesized?

Q.

Who coined the term auxin.

Q. Describe an experiment which demonstrates that growth stimulating hormone is produced at the tip of coleoptile.

[Review question: Pg. No: 241]

Q.

Which of these hormones is not used to produce seedless fruits?

1. Auxin
2. Gibberellin
3. Cytokinin
4. Ethylene

Q. Which of the following is NOT an auxin?

1. IAA
2. IBA
3. Zeatin
4. NAA

Q.

Identify the hormones involved in​

(iii) Production of parthenocarpic fruits​

Q. Positive geotropic movement of root in a horizontally placed seedling is due to

1. New cells that arise on the lower side of root
2. Condensation of cells decrease on the lower side of root
3. Auxins accumulate on the upperside of root, so cell elongation decreases in that area
4. Auxins accumulate on the lower side of root, so cell elongation decreases towards lower side

Q. Describe an experiment which demonstrates that growth stimulating hormone is produced at the tip of coleoptile.

[Review question: Pg. No: 241]

Q. Avena coleoptiles exhibit phototropism when exposed to unilateral light. This is due to -

1. More rate of growth on the light exposed side

2. Less rate of growth on the light exposed side
3. More concentration of auxins on the exposed side.
4. Less concentration of auxins on the shaded side.

Q.

Match the following columns.
$\begin{array}{cccc}& \text{Column I}& & \text{Column II}\\ \text{A}& \text{Zeatin}& 1& \text{Flowering hormone}\\ \text{B}& \text{Florigen}& 2& \text{Synthetic auxin}\\ \text{C}& \text{IAA}& 3& \text{Cytokinin}\\ \text{D}& \text{NAA}& 4& \text{Natural auxin}\end{array}$

1. A-3, B-4, C-1, D-2

2. A-4, B-1, C-2, D-3

3. A-3, B-1, C-4, D-2

4. A-2, B-1, C-4, D-3

Q. The rate of growth in roots is decreased by one of the following plant hormones. This plant hormone is :
(a) gibberellin
(b) auxin
(c) cytokinin
(d) ethene

Q. What would happen if gibberlin is added to rice seedling.
(1 Mark)